1. Field of the Invention
The present invention relates to a method of unlocking the anti-starting system of an engine control computer.
2. Description of the Related Art
The engine control computer is one of the many computers present in a vehicle. It is used to manage, in real time, all the operating parameters of the engine.
The engine control computer conventionally incorporates an electronic anti-starting system, specific to the motor vehicle in which the computer is intended to be fitted and making it possible to prevent the use of the engine of the motor vehicle by an unauthorized person. More particularly, said electronic anti-starting device inhibits one or more functions that are essential to the operation of the engine (cutting the fuel feed for example, or even cutting the ignition on a controlled-ignition engine, etc.) if it does not recognize a known user authorized to start the vehicle. This authentication is obtained by means of an ignition key, an identification badge, or any other equivalent means. Until authentication takes place, the anti-starting device remains active, the computer is therefore unable to operate normally and it is impossible to start the engine.
The locking of the computer is therefore linked to the status supplied by the anti-starting device and its unlocking by means of the key specific to said vehicle requires it to be fitted on the original vehicle.
Now, there is a need to be able to unlock the anti-starting system of the engine control computer and thus to allow the operation of the engine control regardless of the status given by the anti-starting function. This need exists, for example, for engine test bed validation procedures that are necessary in manufacturing or in the context of the after-sale return of the computer for diagnostic purposes. In such situations, since the computer is automatically locked by the anti-starting system, no access to said computer is possible.
Conventionally, a method of accessing a locked engine computer that is not fitted on the original vehicle consists in reprogramming the embedded software so as to inhibit the anti-starting function. This solution does, however, involve irreversibly modifying the embedded software, which makes any subsequent diagnosis of the state of the software impossible. Furthermore, the unlocking of the computer is definitive, so said computer can then be installed on any vehicle, which poses security problems and is therefore unacceptable.